Acrylic modified anionic water dispersible styrene (meth)acrylonitrile copolymers

Abstract

This invention provides a graft copolymer of at least one acrylic monomer and a random copolymer of a styrene and (meth)acrylonitrile, in which at least about 8 percent of the total weight of said graft copolymer is derived from acrylic acid, methacrylic acid, or both. It also provides anionic aqueous dispersions of such graft copolymers and coating compositions containing them.

What is claimed is: 
     
       1. A graft copolymer of an acrylic monomer or monomers or of acrylic monomer or monomers and other monomers copolymerization therewith and a random copolymer of a styrene and between about 20 weight percent and about 30 weight percent of the random copolymer of (meth)acrylonitrile, in which at least about 8 percent of the total weight of said graft copolymer is derived from acrylic acid, methacrylic acid, or both. 
     
     
       2. The graft copolymer of claim 1, wherein the styrene is said random copolymer is styrene. 
     
     
       3. The graft copolymer of claim 2, wherein said acrylic monomer and other monomers copolymerizable therewith are methacrylic acid, styrene and butyl acrylate. 
     
     
       4. A graft copolymer according to claim 1, 2 or 3 wherein the graft copolymer is formed by solution polymerization.